In a bowl, combine the ingredients for the Beef Marinade. Add the beef and let marinate for 10 minutes at room temperature.

In a small bowl, mix together the ingredients for the Stir-fry Sauce.
In a wok or large sauté pan, add 1 inch (2.5 cm) of water and bring to a boil. Add the broccoli and cover to steam for 3 minutes. The broccoli should be bright green, crisp tender and you should be able to pierce the stem with a fork. Drain.

Discard the water in the pan and dry the pan well. Set the pan over high heat and when hot, add the high-heat cooking oil and swirl to coat. Add the garlic and fry for 15 to 30 seconds, until fragrant. Add the steak strips, keeping them in one layer and fry 30 seconds. Flip the strips and fry the other side.
Pour in the Stir-fry Sauce and stir to combine. Simmer until the sauce is thick enough to coat the back of a spoon, about 30 seconds. Add the cooked broccoli back into the pan and toss to coat well.